Usually, the absorbent pads comprise an absorbent matrix made from natural fibre particles (known as “fluff”) blended with particles of absorbent polymer material (“SAP”).
In order to increase the absorption capacity, absorbent pads have been developed which are equipped with one or more discrete layers of particles of absorbent polymer material (“SAP”), positioned on the absorbent matrix.
There are prior art units for making absorbent pads which comprise a drum for forming the absorbent pads and a hood for feeding natural fibre particles and particles of absorbent polymer material. More specifically, the hood has a chamber for mixing natural fibre particles and particles of absorbent polymer material designed to define the absorbent matrix and a dispensing opening facing at least part of the peripheral surface of the drum.
With regard to the feeding of the particles of absorbent polymer material (“SAP”) of the mixing chamber, the unit comprises a first feed duct which leads into the mixing chamber.
In order to make the one or more discrete layers of particles of absorbent polymer material (“SAP”), the unit comprises a second duct for feeding the particles of absorbent material (“SAP”) which leads close to the dispensing opening.
Generally, the second feed duct feeds the particles of absorbent material intermittently to make the discrete layers of particles of absorbent polymer material.
The particles of absorbent material which are not dispensed from the second feed duct are introduced again into the distribution plant of the second feed duct until they are subsequently dispensed from the second duct.
However, it has been found that the recirculation operation deteriorates the absorbent, adversely affecting the capacity for absorption and drainage of liquids.